du pont



'Y n fr F. Du PONT.

PROCESS 0F PREPARIN`G EXPLOSIVE CHARGES FOR SHEILLS..

APPLICATION FILED MAR. 8. I9IB.

1,308,347. Patented Ju1y1, 1919.

2 SHEETS-SHEJET 2.

1 fron/wry yUNITED STATES PATENT. GFFICE. y

IRANcIs I". nu PONT, OF WILMINGTON, DELAWARE, AssIGNOR To YBALL GRAIN EXPLO- sIvEs COMPANY, or WILMINGTON, DELAWARE, A CORPORATION or DELAWARE PROCESS 0F PREPARING EXPLOSIVE CHARGES FOR SHELLS.

Specification of Letters Patent.

Patented July 1, 1919.

Original application led May 2, 1916, Serial No. 94,947. Divided and this application illed March 8, 1918. Serial No. 221,310.

To all whom it may concern.'

Be it known that I, FRANCIS l. DU PONT, a citizen of the United States, A residing at Wilmington, in the county of `New (,astle and State of Delaware, have invented a new and useful Improvement in Processes of PreparingExplosive Charges for Shells, of which the following is a full, clear, and exact description, reference being had to the accompanyinodrawings, which form a part of this specification. y This application is a division of an application led by me' May 2, 1916, Serial No. 94,947.

The connection between the time fuse Aof a shrapnel shell and the bursting yis generally a series of short cylinders of yzo compressed blackl powder. Each of these cylinders has a hole extending axially therethrough. The object of this arrangement is to produce the quickest possible transmission of fire from the timel fuse in the head of the shell to vvthe bursting charge in the base. The theory of operation of the device s that the hole remaining open, the* flame will instantly pass through the column of pellets and fire the bursting charge without variation in time of bursting being produced by the fire having to penetrate through a column of owder which may have become packed 4tigiit by its own inertia when the shrapnel shell is Astarted in motion in the The practical way in which this works out is that there being ei ht cylinders or pellets (as they are called) and these being necessarily a somewhat loose fit in the central tube of the shell, it is nearly impossible to avoid having the cylinders nearest the burstin charge crushed, in the act of iring the Shel from the gun, by the accelerating force acting against the inertia of the pellets ahead of them.' This. plugs the central tube with powder resulting from the crushing of therear pellets and causes variation in time of explosion of this shell.

I have discovered a`certain wa in which this can be prevented and bypwhich the accuracy sought by this method of connecting the tlme fuse with the bursting charge of the shrapnel shell may be fully 'realized M method consists in pressing the powder into a tube to be inserted intothe central tube of lthe shell, 1n Suchel way that a charge having a moisture content of about three per scent., with a liquid having no solvent or chemical action upon the powder, and immiscible with water, preferably gasolene ora liquid of similar properties, and tampingv the mixture in a thin metal cylinder, thereby not only consolidating the powder but also causing the larger volume of the gasolene to exude, and then drying the powder, at an elevated temperature, in the cylinder to drive oil'l the gasolene and moisture. In the drying operation itvmight be supposed, from the action of other material under similar' conditions, that the powder charge would shrink so that its diameter would be reduced sufliciently to cause it to be readily slipped from the mold. If this would Occur, it would produce a unitary charge having some real advantageover the present charge of a number of short Ilets, but it would not accomplish the main object of the present invention. As a matter of fact it is found that if any shrinkage occurs, it does not opcrate to reduce the diameter of thecharge,

but on the contrary the owder charge, after thedrying operation, is ound to be sotightly packed within the container as to resist ejection. By utilizing the tubular container with the charge acked therein as a substitute for the vstring of separately formed pellets, the objects and advantages of my invention are attained.

In carrying outthe process for manufacturin my improved charge I utilizepreferab y an a paratus constructed in accordance with t e accompanying drawings, in which- Figures 1 and partly in section of the entire apparatus, the upper part of Fig. 2 being a continuation of Fig. 1. Fig. 3 aplan view of the lower and main part of the apparatus. Fi 4 is a longitudinal sectional v view of t e finished product.

The explosive powder, together wlth gasoy amount of addcd'should be sufficient to cover the pow- -The amount will vary wit Y lliquid used and it will also vary with other.. conditions; but, as an example, it may be lene, is placed in a tank a containing a revoluble stirrer b, whereby the powder may .be kept in suspension in the asolene.-

gasolene or equlvalent liquid der and render the 'mass caabe of flowiilig. t e particu ar stated that with the mixing operation com ducted at a temperature of 20 C., equal parts by Weight of the -powder and gasolene will. be foun efficient.

After the powderhas been stirred intoa condition o f uniform suspension in the gasolene, the fluid mass is transferred, bymeans of a centrifugal pump c, 'through av tube d, into a vessel e. At oneend ofthe vessel e is an overiiowcha-mber f, lspaced from the .vessel e by a wall'g, over the top of which. i the liquid mass overflows so as to maintain constant the level of the. vessel e. Apipe conducts -the overflow lhack. to the mixing tank a. Within the vessel e is a stureni,

which continuously agitates'themixed pow: der and gasolene," this being necessary`t0. prevent settlement of the owder, which would otherwise occur quic y. v `1 .Arranged along) oneside of the .Vessel e is a chargingA cham er j. The bottom 'ofthe vchamber y' is raised much above the level of 1 the bottom of vessel e. In operation, cham- .ber j is .in open communication with vessel e,

Sothat the two form virtually a unitary charging chamber; but a gate It', atthe conclusion of the mold filling and tampingoperation, may be manually applied to `sepaably of thin metal.` Each. holderis threaded in a supporta secured to the frame .ofthe apparatus.

'n.is apin-o.

the base of a hollow plunger @which is of a diameter, at its base, adapted to loosely t the tube n. .Each plunger p extends'into a cylinder-1- and carries a i on head .s which works inthe cylinder. v ach cylinder has pipe connections tand a valve u whereby itpneumay be .-reciprocated hydraulically,

ers may matically,4 or bysteam.. .The cylin one main' at the 'bottom and one valve will then operate them in unisonf Hydraulic actuation presents decided advantages, but it is of the utmost importance that no water .'should be allowed to reach the powder. ln-

steadof using an'ordinary studinfgbox, l

.prefer to provide the piston' bushing with The pin o, which is fixed, displaces a certainyol fume of air. l.An opening in' the-wall of the 1.

leak thereinto.

amount of t e mixture ows` `intojtlieg.tubes until the: tubes vare filled, V l .understood thatthe plungers arenot car- .theplungers operate .'independently', so y evenjwhenoperated by the same valve each 'Extending centrally throu h each holder" .l m and along the axis of the tu lThe upper end of this pin extends through an annular chamber -o which is connected i throu h apipe fw with a vacuum. pump,

Where. y `any watervthat leak from the cyl; 'inder Wm PaSS'IlO the chamber v and Withdrawn through the w.

On the down stroke of the plunger'p'th plunger permits this airto escape."'andiaf-y fordsalso an outlet for any liqui hat-may Assume that the talikiia land vessel 'ci-are'v filled, the pump in operation, and .the gate c positioned to .exclude 'the-flowfofthe..mixed powder .and gasolenc""`into'f the`"charging'so `l chambery. The pins'ohave been withdr'awn- .anda the holders m havebeen screwedl .down

Lto-allow ofthe insertion 'ofthe tubes n,v The i 1 tubes 'n are now placedm" pt nsition and -thej respective'holders arefscrewed 'uptocona5'. fine' the tubes n thenozzles :fg/' The sitionedi as ..shown inf.` the andthe gates .are removedlj A-Atamh u' lia of the; lungeiaf ace n so'as to fill them1 (say) 'to about one-sixth`-v` ofitheir capacity-before the plungers, on. ,their downstroke,enter the tubesand therel 1 byfclo'sethe lmouths' thereof. The p'lnges 96- seachdescend with suilicient .force to tamp the explosive vto the .desired density, -much the larger portion o f the gasolene Abeing` thereb exuded and forced upwardly out of the tu 'n between-the walls thereofand the'plungers. This operation is repeated It will, be

will exert its own pressure independentlyof. whether or. not the amounts fof- Apowder. 5in@ the tubes are-exactly the same'. et

After the tubes n are filled, the'gatek. is" replaced, the holders m lowered, the pins o.. removed, and theitubesjmnow .lled with'- compacted powder, withdrawn. vThe pow' (le-1 cylinder'sif 10 l.are dried at anelevated y temperature I (say 'about .110 (3.), and .the 29 gasoleneand moisture-:that :hasremained in .the powder wmfbe'difivem-ae. neanche'. be connected to one main at the top and to.

drying Yop'eration the powlder 1 cylinders are of 4a.denszuiy and cohesivene'ss corresponding to the separate .pellets now4 inuse and 1125 remain tightly packed within @the'shells and jeannet be removed therefrom loyfa pressure applied to the manufacture of explosive charges for the central tubes. of shrapnel shells, it is obvious that the process is applicable to the charging with an explosive of any tube of such great length` in proportion to its diameter that instead of acting as a mold from which the charge can be ejected, it acts as a. pipe which has been stopped up, and from which no amount of pressure will remove the obstruction, or at least in which the explosive is so tightly pressed that it will not come out'under reasonably severe usage. The point where the ratio between the diameter and length of a cylinder changes the conditions from those of a mold from which the charge can be removed to those analogous to a stoppedup pipe cannot be rigidly defined, this factor varying with the character of the explosive.

. uniformity, hardness and solidity and remain rmly fixed within the tubular container. l f y Having now fully described my invention,

. what I claim and desire to protect by Letters Patent is:

A1. The process ofvpacking an explosive powder charge tight-ly within a tubular container, which consists in mixing the powder with a liquid having no solvent or chen'lical action upon the explosive and successively compressing fractional parts of the mixture to expel a portion of the `liquid therefrom and consolidate the powder into a uniform, dense, hard and solid mass held in rigid relationship with the container.

The process of packing an explosive powder charge tightly within a tubular container, which consists in' maintaining the powder in suspension in a liquid having no solvent or chemical action upon the explosive, fiowing into the container' a fractional part of the liquid-suspended powder re quired for a charge, compressing the same. and repeating the powder-admission and compression operations until the container has received a full charge.

3. The process of packing an explosivo powder charge tightly within a tubular container, which consist in mixing the powder with a suiiicient volume of a liquid having no solvent or Chemical action upon the powder to enable the same to readily flow, agitating the mixture to maintain the powder in a condition of uniform suspension in the liquid, permitting the mixture to flow into` and partially fill the container, tamping the same to compress the powder` and expel a portion 'of the liquid, repeating the filling and tamping ope-rations until Vthe charge is formed, and drying the charge while thus packed in the container.

' In testimony of which invention, I have hereunto set my hand, at Philadelphia,

Penna., on this 7th day of March, 1918.

FRANCIS I. DU PONT. 

